The document provides an overview of climate change and its causes according to scientific consensus. It explains that climate change refers to long-term shifts in weather patterns caused by both natural factors and human activity. While the climate has changed naturally in the past due to factors like orbital shifts, the current warming trend is both faster and of a greater magnitude than past natural changes, making today's climate change unprecedented. The document attributes the current changes to a sharp rise in greenhouse gas emissions from human activities like burning fossil fuels, which have disrupted the natural carbon cycle and caused global temperatures to increase at a dangerous rate.